May 2013 Statewide Summary

Temperature

The unseasonably cold temperatures from April extended (with a short reprieve on the 9th and 10th) well into May. Above normal mean statewide temperatures returned on the 23rd, and stayed until the end of the month. The mean temperature of all first order stations for May was 39.9°F, 3.1°F below the long-term mean of 43.0°F. Eighteen of the 20 First Order Stations reported negative deviations, with Interior and Western stations reporting the most extreme deviations from their expected temperatures. Bettles topped the list with a significant negative deviation of ‑8.2°F. Following Bettles were: Bethel (-6.6°F), Nome (-5.7°F), Kotzebue (‑5.5°F), and Fairbanks (-5.1°F). Barrow reported the largest positive deviation of 1.6°F, followed by Annette with 1.2°F. Fairbanks had its first 50°F day on May 8th, for a total of 215 days since that temperature had last been reached. This is the fifth longest stretch of under 50°F days for Fairbanks in more than one hundred years. For Nome, the first 40°F days was reached on the 25th, for a total of 224 days below 40°F. Details for each station can be reviewed in the table below.

Station

Temperature

Observed (°F)

Normal (°F)

Delta (°F)

Anchorage

45.0

47.8

-2.8

Annette

51.4

50.2

1.2

Barrow

22.7

21.1

1.6

Bethel

35.3

41.9

-6.6

Bettles

36.2

44.4

-8.2

Cold Bay

39.3

40.3

-1.0

Delta Junction

42.7

47.6

-4.9

Fairbanks

44.3

49.4

-5.1

Gulkana

42.9

45.2

-2.3

Homer

43.0

44.5

-1.5

Juneau

48.0

48.6

-0.6

King Salmon

42.5

44.2

-1.7

Kodiak

42.9

44.3

-1.4

Kotzebue

26.4

31.9

-5.5

McGrath

42.2

46.7

-4.5

Nome

31.1

36.8

-5.7

St. Paul Island

32.6

36.2

-3.6

Talkeetna

44.1

47.8

-3.7

Valdez

42.5

47.0

-4.5

Yakutat

43.6

44.7

-1.1

Daily mean temperature deviation from the normal temperature for the mean of the 20 first order stations for May 2013.

May generated an impressive number of record temperature events. For the most part the events tracked with the general temperature trend with low events centered on the cold spell during the middle of the month and new record highs were mostly found during the last four days of the month, with the only exception being the record high in King Salmon on the 10th. McGrath was on the tear in May with a total of six record low events in the middle of the month, followed by four record high events at the end of the month. In addition (not listed) four new daily low maximum temperatures were set during the middle of the month. The high of 86°F recorded in McGrath on the 28th was a new record high for the month of May.

Temperature Records

Date

Station

Element

New Record

Old Record

Year of old Record

05/03/13

Valdez

Low Temperature

31

32

2012

05/10/13

King Salmon

High Temperature

63

60

1970

05/12/13

Bettles

Low Temperature

15

17

1984

05/12/13

Bettles

Low Temperature

15

17

1984

05/13/13

Bettles

Low Temperature

15

17

1984

05/13/13

Delta Junction

Low Temperature

19

24

1952

05/13/13

Fairbanks

Low Temperature

22

27

1954

05/14/13

Bettles

Low Temperature

8

22

1986

05/14/13

Denali Park

Low Temperature

14

17

1957

05/14/13

King Salmon

Low Temperature

23

25

1965

05/14/13

McGrath

Low Temperature

21

25

1992

05/14/13

Nome

Low Temperature

8

10

1939

05/15/13

Bettles

Low Temperature

14

19

1965

05/15/13

Cold Bay

Low Temperature

25

26

1972

05/15/13

Denali Park

Low Temperature

14

20

1965

05/15/13

King Salmon

Low Temperature

21

21

1965

05/15/13

McGrath

Low Temperature

22

24

1992

05/16/13

Bethel

Low Temperature

18

19

1966

05/17/13

Bethel

Low Temperature

13

24

1939

05/17/13

Cold Bay

Low Temperature

27

28

1992

05/17/13

Kotzebue

Low Temperature

4

4

1992

05/17/13

McGrath

Low Temperature

19

24

2003

05/17/13

Nome

Low Temperature

8

9

1953

05/17/13

St. Paul

Low Temperature

19

23

1956

05/18/13

Bethel

Low Temperature

18

23

1986

05/18/13

Bettles

Low Temperature

10

25

1975

05/18/13

Cold Bay

Low Temperature

27

27

1971

05/18/13

Delta Junction

Low Temperature

19

22

1992

05/18/13

Denali Park

Low Temperature

14

23

1979

05/18/13

Eielson AFB

Low Temperature

23

30

1996

05/18/13

Fairbanks

Low Temperature

24

27

1943

05/18/13

King Salmon

Low Temperature

22

27

1974

05/18/13

Kodiak

Low Temperature

30

31

1975

05/18/13

Kotzebue

Low Temperature

2

9

1904

05/18/13

McGrath

Low Temperature

15

28

1975

05/18/13

North Pole

Low Temperature

26

26

1992

05/18/13

Northway

Low Temperature

23

26

1966

05/18/13

St. Paul

Low Temperature

19

22

1956

05/18/13

Tanana Airport

Low Temperature

18

22

1935

05/18/13

UAF College Obs

Low Temperature

21

25

2003

05/19/13

Bethel

Low Temperature

23

26

1986

05/19/13

Bettles

Low Temperature

10

14

1975

05/19/13

Delta Junction

Low Temperature

24

28

1943

05/19/13

Eielson AFB

Low Temperature

23

29

1966

05/19/13

Fort Yukon

Low Temperature

21

26

1941

05/19/13

Homer

Low Temperature

28

28

1964

05/19/13

King Salmon

Low Temperature

16

26

1964

05/19/13

Kodiak

Low Temperature

28

30

2007

05/19/13

McGrath

Low Temperature

19

28

1985

05/19/13

North Pole

Low Temperature

21

25

1996

05/19/13

Northway

Low Temperature

21

25

1966

05/19/13

Tanana Airport

Low Temperature

14

18

1975

05/19/13

Tok

Low Temperature

19

19

1999

05/19/13

UAF College Obs

Low Temperature

20

26

1983

05/19/13

Valdez

Low Temperature

30

31

1992

05/20/13

Craig

Low Temperature

37

37

1992

05/20/13

Delta Junction

Low Temperature

22

28

1985

05/20/13

Denali Park

Low Temperature

13

23

1982

05/20/13

Fairbanks

Low Temperature

27

28

1964

05/20/13

Juneau

Low Temperature

30

30

1965

05/20/13

McGrath

Low Temperature

27

27

1977

05/20/13

Northway

Low Temperature

13

23

1955

05/20/13

Valdez

Low Temperature

29

30

1966

05/28/13

Bethel

High Temperature

75

74

1997

05/28/13

McGrath

High Temperature

83

81

2010

05/29/13

Anchorage

High Temperature

75

75

2010

05/29/13

King Salmon

High Temperature

77

75

2006

05/29/13

McGrath

High Temperature

86

78

2010

05/30/13

Fairbanks

High Temperature

84

84

1983

05/30/13

McGrath

High Temperature

85

81

2010

05/31/13

McGrath

High Temperature

85

78

1993

Precipitation

May precipitation was heavier than normal with twelve of the 20 stations reporting above average totals. The mean value of all 20 stations was calculated to 35% above normal. Topping the stations with heavier than normal precipitation was Valdez with 271% above normal. Next came: Gulkana (228%), Barrow (122%) and Anchorage (113%). Bettles reported the greatest negative deviation with just 3% of the expected value. Rounding out the stations with less than a quarter of normal totals were: McGrath (6°%), Delta Junction (10%), and Bethel (18%). Details are presented in the following table.

Station

Precipitation

Observed (in)

Normal (in)

Delta (in)

Delta (%)

(%)

Anchorage

1.53

0.72

0.81

113%

213%

Annette

6.83

5.56

1.27

23%

123%

Barrow

0.40

0.18

0.22

122%

222%

Bethel

0.20

1.14

-0.94

-82%

18%

Bettles

0.03

0.88

-0.85

-97%

3%

Cold Bay

3.29

2.60

0.69

27%

127%

Delta Junction

0.09

0.90

-0.81

-90%

10%

Fairbanks

0.15

0.60

-0.45

-75%

25%

Gulkana

2.13

0.65

1.48

228%

328%

Homer

1.15

0.82

0.33

40%

140%

Juneau

5.33

3.40

1.93

57%

157%

King Salmon

0.33

1.25

-0.92

-74%

26%

Kodiak

2.22

5.62

-3.40

-60%

40%

Kotzebue

0.86

0.41

0.45

110%

210%

McGrath

0.07

1.09

-1.02

-94%

6%

Nome

1.79

0.86

0.93

108%

208%

St. Paul Island

0.95

1.13

-0.18

-16%

84%

Talkeetna

3.00

1.62

1.38

85%

185%

Valdez

10.69

2.88

7.81

271%

371%

Yakutat

17.25

8.21

9.04

110%

210%

Daily mean precipitation deviation from the normal for the 20 first order stations for May 2013.

Unsurprisingly, considering the low temperatures during much of the month, snowfall for May was above normal with eight of the sixteen stations reporting heavier then normal snowfall, resulting in an overall mean of 214% above normal. However, much of this positive deviation was from Valdez where more than ten times the normal snow fell during the month; with most of this snowfall arriving during the first five days of the month. Bettles (669% above normal), Kotzebue (425%), Nome (370%), Kodiak (350%) and Anchorage (333%) topped the stations with highly elevated snowfalls. Trace or more of snow was recorded for 24 days of the month in Barrow.

Station

Snowfall

Observed (in)

Normal (in)

Delta (in)

Delta (%)

(%)

Anchorage

1.3

0.3

1.0

333%

433%

Annette

0.0

0.1

-0.1

-100%

0%

Barrow

5.4

2.7

2.7

100%

200%

Bethel

0.0

2.1

-2.1

-100%

0%

Bettles

10.0

1.3

8.7

669%

769%

Cold Bay

0.3

1.3

-1.0

-77%

23%

Fairbanks

2.0

0.9

1.1

122%

222%

Juneau

0.0

0.0

0.0

King Salmon

0.8

0.8

0.0

0%

100%

Kodiak

0.9

0.2

0.7

350%

450%

Kotzebue

6.3

1.2

5.1

425%

525%

McGrath

0.7

0.9

-0.2

-22%

78%

Nome

10.8

2.3

8.5

370%

470%

St. Paul Island

0.0

1.1

-1.1

-100%

0%

Valdez

27.3

1.9

25.4

1337%

1437%

Yakutat

0.0

0.4

-0.4

-100%

0%

A large number of precipitation and snowfall records were set in May; many of them centered on the storm events of in the Southeast on the 1st, and in the Southcentral / Interior areas on the 3rd and 4th. A number of the snowfall events occurred on days for which snowfall had never been recorded before. The cold temperatures, the prior months' snowfalls as well as heavy May snowfalls in Valdez resulted in a mean snow depth for the month of more than twenty times normal. May was the snowiest on record in Nome with a total of 10.8", topping the 1977 record of 10.0".

Precipitation Records

Date

Station

Element

New Record

Old Record

Year of old Record

05/01/13

Annex Creek

Precipitation

1.03

0.80

1980

05/01/13

Haines Airport

Precipitation

0.58

0.58

1980

05/01/13

Juneau

Precipitation

0.91

0.76

1980

05/01/13

Ketchikan

Precipitation

3.68

2.01

1980

05/01/13

Petersburg

Precipitation

1.39

0.78

1993

05/01/13

Port Alexander

Precipitation

3.05

0.89

1980

05/01/13

Sitka

Precipitation

1.05

0.95

1999

05/03/13

Fairbanks

Snowfall

1.30

0.60

1958

05/03/13

McGrath

Snowfall

0.70

0.40

2008

05/03/13

Valdez

Precipitation

2.72

1.30

1998

05/03/13

Valdez

Snowfall

10.80

8.60

1998

05/04/13

Anchorage

Snowfall

0.90

0.40

2001

05/04/13

Anchorage

Precipitation

0.36

0.32

1989

05/04/13

Valdez

Precipitation

2.06

0.83

1972

05/04/13

Valdez

Snowfall

3.90

2.30

2001

05/14/13

Valdez

Precipitation

1.06

0.72

1989

05/15/13

Nome

Snowfall

1.90

0.80

1976

05/16/13

Valdez

Snowfall

1.30

0.00

05/17/13

Anchorage

Snowfall

0.30

0.20

1989

05/17/13

Anchorage

Precipitation

0.52

0.21

1959

05/17/13

Valdez

Precipitation

1.05

0.70

1997

05/17/13

Valdez

Snowfall

0.50

0.00

05/19/13

Craig

Snowfall

0.00

0.00

05/19/13

Juneau

Snowfall

0.00

0.00

05/20/13

Kotzebue

Snowfall

1.10

0.30

1964

05/21/13

Nome

Snowfall

4.20

0.50

1990

05/21/13

Nome

Precipitation

0.81

0.55

1960

05/21/13

Nome

Monthly Snowfall

10.80

10.00

1977

05/26/13

Cold Bay

Precipitation

0.80

0.53

1982

05/31/13

Juneau

Precipitation

1.10

0.81

1948

This infrared satellite image from the National Weather Service shows strong late winter system affecting the Southcentral and Interior portions of Alaska on Friday, May 17th, 2013. This late winter storm drove snow and rainfall across the region.

Newsworthy Events

The tempest of the 3rd of the month brought winter storm warning across much of the state. More heavy snows in the 6th dropped up to two feet in Nabesna and Mentasta Pass. Storm warnings were again issued on the 13th for much of the state, and hazardous driving conditions were reported on the Dalton and Parks Highways. The Dalton also saw an unprecedented number of avalanches during the month, and they continued up to the end. Despite ongoing work by the road crews, the Denali Highway was not opened to summer traffic by the 31st.

The cold weather also resulted in later than normal break up across many of the rivers. Flooding from an ice jam on the Yukon hit Eagle on the 17th. Flooding moved down river to Circle on the 19th, with the locals calling it the worst flood to ever hit the community. Fort Yukon residents prepared to be next, but the town was mostly spared. Heavy flooding next hit Galena on the 26th, resulting in most of the town being evaluated. Water did not recede until the 28th. Minor flooding was reported along the Salcha River around the 25th. The Steese Highway was closed due to flooding on the 28th.

By mid month the unusual weather was having its effects felt in the annual migration of many bird species that travel through the Interior. The Nenana Ice Classic recorded its latest break up on record on the 20th. The annual guessing game has a 97-year record. Finally, Green-Up-Day for Fairbanks was recorded on the 26th, which was also the latest on record.

This information consists of preliminary climatological data compiled by the Alaska Climate Research Center, Geophysical Institute, University of Alaska Fairbanks. This summary is based on the 20 first order stations in Alaska operated by the National Weather Service. Extreme events of other stations are also mentioned. It should be noted that the new climate normals for the time period of 1981-2010 are applied for the calculations of the deviations, and they can be slightly different from the old normals (1971-2000), which were in use up until end of July 2011.